Genotype × Environment Interaction in Sweet Potato ( Ipomoea batatas L.): Assessing Stability of Yield per Plant Across Six Diverse Environments

Genotype × environment (G × E) interaction is a key factor influencing the selection of stable and high‐yielding sweet potato ( Ipomoea batatas L.) cultivars across diverse agroecological zones. The complexity of G × E interaction often leads to biased yield estimates in multienvironment trials, hindering phenotypic selection and impede breeding progress. This study aimed to evaluate the yield stability and adaptability of seven elite CIP‐developed sweet potato genotypes across three diverse locations in Bangladesh—university research field, farmers’ field, and the Brahmaputra riverbank char land—over two successive growing seasons in 2023 and 2024. To ensure experimental precision, a randomized complete block design (RCBD) with three replications was adopted. To assess phenotypic stability, the additive main effects and multiplicative interaction (AMMI), genotype + genotype × environment interaction (GGE) biplot models, and the multitrait stability index (MTSI) were employed. The combined analysis of variance revealed significant genotype × environment (G × E) interactions for most of the studied agronomic and nutritional traits. Pearson’s correlation analysis showed strong positive associations among key nutritional and yield‐contributing traits. The AMMI and GGE biplot models explained over 85.4% of the total variability, highlighting their effectiveness in analyzing G × E interactions. Genotypes G353 and G310 were consistently high‐performing and stable, while G15, G138, and G5 showed environment‐specific adaptation to E6 and E3, respectively. The riverbank char lands (E3 and E6) generally exhibited high mean yields and strong discriminatory power for genotype evaluation. Based on the MTSI method, G353 was identified as the most stable and productive genotype. The study revealed substantial genotype × environment interaction effects on the yield performance of sweet potato genotypes across diverse environments of Bangladesh and provided useful guidance for future breeding programs.